Blow-off device for steam boilers



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Patente Apr. 19, 1927..

UNITED STATES Enwm oALnwELL, or nnmmenam, Anne,

mmruracrunme ooMrANY (ma), a ooonarron' or ,14525307 ATENT oFFicE';

essmnon 'ro rnY-catnwatn BLUW-OFF DEVICE FOR S'I'E IBUHZEES.

application filea January ai, taaa serial no. a-,eia

The present invention relates to improvements in Cleaning devices for steam boilers, and the primary object of the invention is toprovide means whereby the boiler will be relieved not only of sedinient and scaleforming substances which are in Suspension in the boiler water, but which is capable of removing from the boiler scale-forming substances, such, for example, as salts and similll lar soluble mat-ters which are in solution in the boiler Water and., hence, are incapable of removal from the boiler water by boiler cleaners of the kinds heretofore proposed which depended upon filtration, precipitation or settling' of the scale-forming' substances.

According to t-he present invention, water is continuously blown od' from thebOiler, from a point below the water line thereof W and' preferably at or near the bottom of the boiler where the sediment accumulates and the impurites or scale-forming substances are concentrated9 under the automatic control of an orifice or nozzle", the size of which is proportioned in accordance with the capacity of the boiler and the pressure at which it is operated, andthe water thus blown ofl" is discharged into a sewer or is otherwise discarded The salts or other scaleforming substances in solution 'in the boiler water are thereby removed from thev boiler, and, hence, they cannot become concentrated as the result of evaporation to form scaleA or deposits on the heat-ing surfaces of the boiler. The removalV of the boiler water containing scale-forming substances in solution therein also removes from the boiler scale-forming matters in Suspension 'therein.

By continuously withdrawing water from 40 the boiler, and especially from the lower portion thereof, through an orifice or nozzle of appropriate size, the boiler water is lrept substantially clear of scale-forrning substances, including those in solution as well 'w as those in Suspension, and these substances are removed from the boiler automaticallyJ or without requiring the attention of an at- -tendant/ To these and other ends, the invent-ion consists in certain improvements and combinations and arrangements of parts, all as will be hereinafter more fully described, the features of novelty being pointed out part-icularly in the claims at the 'end of the specification.

lin the accompanying drawing:-- Figure 1 is a sectional view of a boiler blow-off device constructed'ini accordance with the present invention; and

Figure 2 is a diagrammatic view showing the blow-od device operatively connected to a steam boiler.

Similar parts are designated by the same I reference characters in the several views.

The present mventlon is applicable generally to steam boilers of various, types. where it is desirable or necessary to prevent stricted to lthe precise construction shown,

as' equivalent constructions are contemplatc ed, and such will be included within the scope of the claims.

lln the present instance, 1 designates a portion of a steam boiler which may be of any of the types known or used, and 2, Fin. 1, or 2, Fig. 2, represents a blow-off pipe which leads from the bottom or lower ortion of the boiler, and it may be the b owoff pipe which has heretofore been'used generally on steam boilers for the purpose of blowing of boiler water therefrom., it having been the previous practice to blow off boiler Water through such a blow-od' pipe periodically by opening a valve attached to the blow-off pipe. Howeven the dischargeof boiler water at intervals` as has been the usual practice,'does not effectively prevent the deposit of scale in the boiler,

as during the intervals between the blow-off operations,'the Scale forrning impurities collect or become concentrated in the boiler water, due to the evaporation of the Water, and a considerable amount of these im urities will become deposited and will orm Scale in the boiler notwithstanding the periodic blowing ofl' of water therefrom, as has been heretofore practiced. lt has been proposed to Withdraw water from the boiler` andv after subjecting the withdrawn water to filtration, precipitation or` settling, to return such water to the boiler, but such methods/Would not be effective Ito .prevent the formation of scale in the boiler as' the salts .'or other soluble scale-forming substances are in solution in the water, they cannot be i separated therefrom by the' methods prewhich operates c'ontinuously and automatically to discharge water from the bottoni or lower portion of the boiler where sedi ment'or substances in suspension collect and impurities or substances in solution in the water are concentrated. The rate of discharge of the water is regulated automatically by an orifice or nozzle, the size of which is properly proportioned to 'suit the steaming capacity of the boiler` and the pressure at which it is operated. This orifice or nozzle receives the boiler water at or substantially at boiler pressure and it discharges it into a sewer or other means of disposal, the difference of pressure at the inlet and discharge sides of the orifice being constant or substantially so and sufficient to insure the continuous and effective discharge of water from the boiler at a rate which is regulated lautomatically according to the size of the orifice and pressure at which the' boiler'is operated. By withdrawing boiler water in this manner, accumulation and deposit of scale-forining sub:tances in the boiler is prevented as the salts or other soluble scale-forming substances which are in solution in the water, as well as the sediment and other impurities which are in Suspension in the water are continuously withdrawn from the boiler sov that accumulation and concentration of these scale-forming substances, due to evaporation of the water, cannot oceur, and as the water thus withdrawn from the boiler is discharged into a sewer or 'otherwise discarded, there is no opportunity for the return of 'the soluble impurities to the boiler.

The device, in the embodiment of the iiivention herein shown, comprises a recepta- `cle 3 which may be cylindrical or otherwise formed in cross-section and is elongated vertically to provide a Chamber ll of appropriate height. The top andbottom of the -receptacle are closed and the receptacle is so constructed that it is capable of withstanding boiler pressure. An inlet pipe 5 is threaded or otherwise fitted into the upper head of the receptacle and projects downwardly within thellatter to a point near its bottom, the lower end of this inlet pipe being open. The upper end of the inlet pipe is suitably connected to the boiler or boilers with which the device is used. As shown, the upper end of the inlet pipe has attached thereto exteriorly of the receptacle 3 a pipe fitting 6, this fitting coinprising' preferably a T, the upper end of which is closed by a removable plug 7 which is in, alinement with the inlet pipel 5, and a pipe 8 is attached to the branch connection of the T, the opposite end of this pipe being connected to the branch connection of a T 9, the upper end of which is attached to a gate or other suitable valve 10, which latter,

vin turn, is connected to the boiler or to the blow-off pipe 2 or 2a thereof. A clean-out plug ll is preferably fitted into the lower end of the T 9 opposite to the valve 10. A nozzle 12 is threaded or otherwise fitted into the upper head of the receptaele and it projects downwardly into the upper end of the Chamber 4, the nozzle having a vertically, axially elongated orifice 12a which has a cross-section which is appropriately proportioned to give the desired rate of discharge or continuous blow-off of the boiler water to suit the steamingI capacity of the boiler. The nozzle 12 is connected exteriorly of the receptacle'3 to suitable piping which leads to a sewer or other point of disposal. As shown, the pipe T 13 is connected at one end to the nozzle, its opposite end in line with the nozzle being provided with a cleanout plug 14, and the lateral branch of the T is connected to a pipe 15 which serves to conduct the water discharged from the nozzle to the sewer or point of disposal.

The pipe 15 is prefcrably open at its end to the atmosphere so that back pressure on the nozzle is substantially eliminated. Suitable means is provided for discharging sediment which may collect in the bottom of the chamber 4 of the receptacle, a discharge valve 16 being shown for this purpose, the valve being connected to the lower head of the receptacle.l

Theimode of operation of the blow-off device is as follows: VVhen the boiler has been steamed up,4 the drain valve 16 is closed, and the valve 10 is opened, and the latter valve reinains open during the operation of the boiler. The pressure in the boiler forces the boiler water from the bottom or lower portion thereof out through the valve 10, pipe 8 and inlet pipe 5 into the lower portion of the Chamber 4-, and this water rises in the latter Chamber and discharges through the contracted ori' fice 12*L of the nozzle 12 into the discharge pipe 15 through which it is conducted to the sewer or place of disposal. The blowoff of the boiler water takes place continuously during the operation of the boiler and the rate of discharnfe of the water is regulated automatically hy lthe size of the orifiee of the nozzle, and. hence, the device is automatic in its operation. The continuous withdrawal of water from the bottoni or lower portion of the boiler removes from the boiler any sedirnent andw iinpurities which are either in solution or in Suspension in the boiler water, these impurities being more concentrated in the bottoni or lower portion of the boiler, and, hence, there is neaaro'r no opportunity for concentration of these impurities to a degree 'to cause Scale-forming deposit of these impurities upon the heating surfaces of the boiler. By appropriately proportioning the size of the orifice in the nozzle according to the steaming capacity of the boiler., the continuous blow-od of water from the bottom or lower portion of the boiler may take place at a rate which willsubstantially eliminate any substantial degree of concentration of the salts or soluble scale-forming impurities in the boiler water, and will substantially prevent accumulation of sediment or impurities in Suspension in the boiler water. o

The valve 16 connected to the bottom of the receptacle 3 may be opened occasionally to drain from the chamber 4 any sediment or solid impurities which may accumulate in the receptacle, and the plugs 7., 11 and lt may be removed at any time if necessary to clean out the pipe 5, valve 10 or the nozzle 12. ft will be understood that the device may be connected to serve one or morev boilers, if desired, and that the device may he connected in difierent ways to the boiler or boilers or to a blow-od pipe connected thereto. By locating the orifice device or nozzle in the uplperportion of a chamber which receives t e boiler water, it is protected from clogging by sediment or solid particles that may be carried over by the water., as such sediment or solid particles will be trapped in the lower ortion of the chamber, and they may be 'ained ofi' by occasionally opening the drain valve at the bottom of this chamber. nlargement of the orifice under the cutting action of the water discharging therethrough is substantially avoided by axially elongating the orifice substantially to the extent shown, and clogging of the orifice by sediment is avoided, as the orifice is arranged vertically and it leads upwardly from the upper portion z of the sediment interceptingreceptacle.

The automatic blow-off devlce embodying thepresent invention not only prevents the formation of scale in steam boilers but it also prevents *foaming of the water by reason of the reduction which it effects in the concentration of the matters in Suspension and in solution in Ithe boiler water. Consequently, it effects a great reduction in the loss of water which has heretofore been carried off from the boiler with the steam as theI result of foaming.

I clam as m invention:-.-

l. A blo'w-o' device for steam boilers comprising a receptacle having means for connecting it to receive water from the watel` space of a boiler,-and refuse-water discharge means leading from said receptacle at a point' removed from the path of the boiler water entering it and,having a restricted orifice leading upwardly from the 3. A blow-ofii device for steam boilers comprising a receptacle having means extending to the lower portion of the receptacle for pconducting water thereto continuously from a boiler and constantly open refuse-water discharge means leading from the top of said receptacle and having a restricted nozzle projecting downwardly from the top ofl the receptacle for continuously discharging said water therefrom at a rate determined by the size of said nozzle.

4. The combination with a steam boiler,

of a blow-ofi pipe for continuously dischai'gingn water from the water space thereof, and constantly open refnse-water discharge means comprising a restricteddownwardly directed orifice device connected to receive the water from the blow-OE pipe by an up- Ward fiow of the water and operative to discharge such water continuously underthe influence of the boiler pressure and ata rate determined by said orifice device.

o 5. A blow-ofi' device for steam boilers comprising a receptacle having means for connecting it to receive water from the water space of a boiler, and constantly open refuse-water discharge means comprising a constantly open relatively contracted axially elongated orifice of fixed size leading from said receptacle at a point removed from the path of the water entering it from the boiler for continuously discharging the boiler water received b the receptacle at a rate determined by t e size of said orifice.

6. A blow-ofl device for steam boilers comprising a sediment-intercepting receptacle having means for connecting it to the water space of a boiler to receive boiler water therefroxn, and constantly open refusewater discharge means leading from the top of said receptacle and having at itsI point of communication therewith and leading lupwardly therefrom a substantially Vertical relatively contracted constantly open orifice of fixed size operative to continuously discharge water from said receptacle to said discharge means and to determine the rate of such discharge.

In testimony whereof I have hereunto set my hand.

` ERWIN CALDWELL. 

